Platinum azides

Mackay, F. S. Photoactive platinum azide anticancer complexes, PhD Thesis, University of Edinburgh, Edinburgh, 2006. 

A normal platinum azide is not known, but complex azides of both Pt(II) and Pt(IV) have been described. When investigating the latter, Curtius and Rissom [62] obtained red solutions of the potassium salt which exploded violently when heated, and a dark red residue, obtained upon concentration, exploded spontaneously with high brisance. The sensitivity disappears in combination with large organic cations or amine ligands, yielding compounds that decompose slowly when heated but are stable to impact. They are, however, photosensitive and will deteriorate within hours or days. 

Also unexpected is the formation of the 2,2 -(3,4,5,6,7-pentafluoroazepin-2-ylidene) (35) during the flow pyrolysis of perfluorophenyl azide over platinum at 300 C.6°... 

Neruda, B. et al., J. Organomet. Chem., 1976, 111, 241-248 In the exothermic reaction with trimethyl phosphite to give r/.v-dimethyl-bis(trimethyl phosphito)platinum, the azide must be added to the phosphite in small portions with stirring. Addition of the phosphite to the solid azide led to a violent explosion, probably involving the transitory by-product methyl azide. 

See related METAL AZIDES See other PLATINUM COMPOUNDS... 

See other platinum compounds See related metal azides... 

Intramolecular nucleophilic additions by nitrogen functional groups onto pendant alkynes and allenes represent an important class of type la approaches to functionalized pyrroles. A platinum-catalyzed (PtCl4) cyclization of homopropargyl azides provided an entry to 2,5-disubstituted pyrroles and 4,5,6,7-tetrahydroindoles (fused pyrroles) <06OL5349>. 

Table 11 summarizes results of spin trapping experiments where PBN-Nu and other ST-Nu" systems have been oxidized anodically at platinum. Originally, all the reactions were suggested to proceed via Nu radicals (Janzen et al., 1980 Walter et al., 1982), but the fact that PBN is oxidized at a lower potential than Cl-, CNO and CN- (Tables 1 and 5) clearly shows that the faster electrochemical process must be PBN— PBN + at the potentials employed. On the other hand, azide ion is oxidized in a faster reaction than any of the spin traps used and thus azide radical is implicated as being trapped. The Cr 4MePyPBN [17] system is a case where possibly Cl is involved in view of the high pa of this spin trap. 

Many nucleophiles act as inhibitors of platinum, palladium and rhodium catalysts. The strongest are mercaptans, sulfides, cyanide and iodide weaker are ammonia, azides, acetates and alkalis [26]. 

The a-D-lyxo epoxide [232, R = (3-deoxy-l,2 5,6-di-0-isopropylidene-a-D-glucofuranose-3-yl), R1 = CH2OH] was converted into a 3,4-unsat-urated D-threo-2,6-diol (268), which was dimesylated and the diester treated with sodium azide. Two diazides (673a and 673b) were obtained and separated the latter was hydrogenated in the presence of platinum catalyst and the product acetylated, to furnish 673c. 

An unusual tetrazene complex of platinum(IV) is obtained from tra/ts-Pt(C CPh)2(PEt3)2 and 4-nitrophenylazide (equation 371).1209 The structure has been verified by crystallography. The analogous platinum(Il) complexes can be formed by reacting Pt(cod)2 with aryl azides followed by triethylphosphine.1210 The complexes with non-symmetrical RN4R ligands are also known.1211... 

Amino-4-methoxy-l-methoxymethylnaphthalene 120, obtained from the chloromethyl derivative 111, is transformed into azide 121. The latter undergoes photolytic heterocyclization to the labile 5-methoxyben-zo[cd]indole 117 which, on reduction by lithium aluminium hydride followed by acetylation, is converted into the stable l-acetyI-5-methoxy-l, 2-dihydrobenzo[o/]indole 119 (R = OMe) [71JCS(C)721]. The reduction of methyl or phenyl 8-nitro-1 -naphthyl ketones by hydrogen and platinum dioxide or by iron in acetic acid leads to a mixture of products (59M634). 

It will be noted that the solubility of azides of the alkali metals increases as the at. wt. of the alkali metal increases and that their solubility in alcohol decreases with increasing at. wt. of the alkali metal. J. A. Cranston and A. Y. Livingstone showed that in the presence of platinum black, the alkali azide is decomposed ... 

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